Safety plug



J. F. TATUM July 11, 1950 SAFETY PLUG Filed July 27, 1948 M 4 Wm w M; w 2 a a I J Patented July 11, 1950 STATES PATENT OFFICE? Q 2,514,911 I c I g, SAFETY PLUG .loscphFranklinTatiiin, Hattiesburg, Miss. Application July 27, 1948, Serial N'c.40,'9-'70 This invention relates to stoppers or plugs and more s particularl-ly' expansible plugs for use in gas mains or water pipes where it is desired to shut off the fluid flow when connection is being made to a new section of piping.

Heretofore, it has been-the practice to use an expansible stopper mounted on" a threaded ma with screw means forexpanding the diameter of the stopper after-it has-been'placed in the desired locationinthepipe." Itis-anbbject of this invention to provide a plug; which can be expanded instantaneously once it is placed in the pipe.

Itis a further objectu-of this invention to provide an -expansible stopper in-which the-compression of a coil spring effects the expansion of the stopper, and which is provided with screw means for compressing the spring and trigger means for relieving the stopper of compression of spring until the device is positioned in the desired point in the pipe.

A further object of this invention is to provide 2 Claims. (Cl. 13889),

a safety lock for the releasing trigger for the purpose of preventing the release of the trigger before the expansible plug is located in the desired position.

, Still another object of this invention is to provide an instantaneously expandable stopper which is simple to use and inexpensive to manufacture, with a minimum number of moving parts.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in nates generally a threaded rod having a nut II carried on one end thereof. Mounted on the rod adjacent the nut II is a washer I2. A rubber expansible plug or stopper I3 is slidably carried on the threaded rod I6 adjacent to the Washer I2. A second washer I4 abuts the other end of the plug or stopper I3.

A tubular member I5 is slidably mounted on the threaded rod I0 and is adapted to abut the washer I4 for moving it to the right for the purpose of compressing the expansible plug I3 between the washers I2 and I4. Arranged about the rod I0 is f a coil spring I6; seating upon, the. hat-shaped spring seats I'i'|1and,I.8:., Intermediate'thelength of the, spring I 6; a spacer- I 9,:is slidably. mountedaon the rod II] for the .purposeof obtaining. a uni formcompress'ion of :the spring, I6. I

At the far end of the rod IIlnf-romthe nutrl I-, a wing nut .26 is threadably engaged with :the .rod Iii; The tubular member ='I5.:is formed with] a slot 2 I for .engagementzabout the upstanding pin 22 which, is fixedly carried bytherod IEI. Mounted on topiof the. tubular member I 51s a trigger gen;- era-llydesignatedby the numeral: 23. The trigger 2 3; *consistsofsa housing. 24n1having .a cut-out: 25 extendingaalong the bottom thereof for, the. purpose; :of accommodatingthe upstanding pjin; 22 carried by the rod Ill.

A latch member 26 is rockably mounted on the housing 24 by the pivot 21. The latch 26 is formed with two split arms 28 and 29 respectively, having a cross pin 30 fixedly mounted therein. A safety lock 3| is provided for the purpose of retaining the latching member 26 in its latching position. The safety lock consists of a bar 35. pivoted from the top of the housing 24 by the screw 32 and having an indent 33 adapted to engage a depression 34 in the top surface of the housing The pivoted bar 35 is formed with a right angled downwardly extending arm 36 having a horizontal portion 31 on the end thereof adapted to engage the arm 28 of the latching member 26.

Operation When it is desired to shut ofi the flow of a fluid in the pipe 46, the latching member 26 is raised depressing the keeper pin 30 which then prevents movement of the pin 22 and the rod II] in which it is fixedly mounted relative to the tubular member I5. The wing nut 20 is then rotated relative to the rod I 0 compressing the spring I6. The expansible stopper is then inserted in the pin 40 and the latching member 26 is depressed, freeing the pin 22 and allowing the spring I6 to force the hat-shaped spring seat l8 towards the right and the spring seat I! towards the left, as viewed in Figure 1.

This will cause motion of the tubular member I5 relative to the rod I0. The tubular member I5 will bear on the washer I4 and the nut II will bear on the washer I2, thereby compressing the expansible plug or stopper and increasing its diameter and thereby shutting off the flow of fluid in the pipe 40.

In order to insure against the accidental tripping of the latching member 26, the safety lock 3I is pivoted horizontally so as to engage the horizontal portion 31 under the arm 28 on the latching member. When the expansible plug is in position the safety lock is centered and the latching member 26 depressed for the purpose of expanding the plug, as explained above.

The details disclosed herein represent a preferred embodiment of my invention. However, I. do not mean to be limited to these exact details but claim all variations covered by the appended claims.

What I claim is:

1. An improved expansion plug for use in fluid carrying pipes comprising an elongated rod having abutments on the opposite ends thereof, an expansible stopper on said rod and disposed against One of said abutments, a sleeve slidable on said rod and engageable with said stopper, spring means interposed between the other of said abutments and said sleeve for urging the latter against said stopper, a longitudinal slot formed. in said sleeve, a pin fixed on said rod and loosely extending through said slot and a lever rockably mounted on said sleeve having a portion engaging said pin in one position for preventing longitudinal movement of said sleeve relative to said rod.

' 2. An improved expansion plug for use in fluid carrying pipes comprising an elongated rod having abutments On the opposite ends thereof, a cylindrical expansible stopper carried by said rod and disposed against one of said abutments, a pin fixed to said rod and extending radially therefrom, a tubular member slidable on said rod engaging said stopper and formed with a longitudinal slot loosely receiving said pin, a 35 trigger on said tubular member including a housing fixed to said tubular member and overlying slot, a lever rockably mounted upon said housing and having a cross pin at one end thereof engaging said first mentioned pin when the other end of said lever is raised for preventing longitudinal movement of said tubular member relative to said rod, and a locking bar pivoted on said housing and in one position engaging under said other end of said lever for retaining said other end in raised position, and a compression spring interposed between said other abutment and said tubular member for constantly urging the latter against said stopper whereby said stopper will be longitudinally compressed for expanding the diameter thereof when said lever is rocked to disengage said cross pin from said pin on said rod.

JOSEPH FRANKLIN TATUM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,117,669 Hall Nov. 1'7, 1914 1,121,847 Kirkwood Dec. 22, 1944 2,390,461 Racy Dec. 4, 1945 2,460,352 Jensen Feb. 1, 1949 FOREIGN PATENTS Number Country Date 373,944 Great Britain Jan. 2, 1932 

